Semiconductor device and method of manufacturing the same

ABSTRACT

A semiconductor device may include a first cell structure, a second cell structure, a pad structure, a circuit, and one or more openings. The pad structure may be disposed between the first cell structure and the second cell structure, and may be electrically coupled to the first and second cell structures. The pad structure may have a plurality of stepped structures. The circuit may be disposed under the pad structure. The one or more openings may pass through the pad structure, and may expose the circuit. The one or more openings may be disposed between the plurality of stepped structures.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. §119(a) toKorean patent application number 10-2016-0080257 filed on Jun. 27, 2016in the Korean Intellectual Property Office, the entire disclosure ofwhich is incorporated herein by reference.

BACKGROUND 1. Technical Field

Various embodiments of the present disclosure generally relate to anelectronic device and a method of manufacturing the same, and moreparticularly to a three-dimensional semiconductor device and a method ofmanufacturing the same.

2. Related Art

Non-volatile memory devices can retain stored data regardless of whetheror not they are connected to power supplies. As a two-dimensionalnon-volatile memory device technology is reaching its physical scalinglimit, some semiconductor manufacturers are producing athree-dimensional (3D) non-volatile memory device by stacking memorycells on top of each other on a substrate.

A three-dimensional memory device may include gate electrodes that arestacked alternately with interlayer insulating layers, and may alsoinclude channel layers passing through the gate electrodes andinterlayer insulating layers. In this way, memory cells may be arrangedvertically along the channel layers. To improve reliability of such anon-volatile memory device having a three-dimensional structure, variousstructures and manufacturing methods are being developed.

SUMMARY

In an embodiment of the present disclosure, a semiconductor device mayinclude a circuit, a pad structure, a first opening, a second opening, afirst interconnection structure, and a second interconnection structure.The pad structure may be disposed over the circuit, and may include afirst stepped structure including first pads stacked on top of oneanother, a second stepped structure including second pads stacked on topof one another, and a third stepped structure including third padsstacked on top of one another. The first opening may be disposed betweenthe first stepped structure and the second stepped structure, and maypass through the pad structure and expose the circuit. The secondopening may be disposed between the second stepped structure and thethird stepped structure, and may pass through the pad structure andexpose the circuit. The first interconnection structure may electricallycouple the first pads and the third pads to each other and couple thefirst and third pads in common to the circuit through the first openingor the second opening. The second interconnection structure mayelectrically couple the second pads to each other and couple the secondpads to the circuit through the first opening or the second opening.

In an embodiment of the present disclosure, a semiconductor device mayinclude a first cell structure, a second cell structure, a padstructure, a circuit, and one or more openings. The pad structure may bedisposed between the first cell structure and the second cell structure,and may be electrically coupled to the first and second cell structures.The pad structure may have a plurality of stepped structures. Thecircuit may be disposed under the pad structure. The one or moreopenings may pass through the pad structure and expose the circuit. Theone or more openings may be disposed between the plurality of steppedstructures.

In an embodiment of the present disclosure, a method of manufacturing asemiconductor device may include forming a circuit on a pad region of asubstrate comprising a first cell region, the pad region and a secondcell region which are successively arranged in a first direction. Themethod may include forming a stacked structure over the substrate onwhich the circuit is formed, the stacked structure including first ton^(th) (n is a natural greater than or equal to three) groups stacked ontop of one another. The method may include partially patterning the padregion of the stacked structure and forming a first cell structuredisposed in the first cell region, a second cell structure disposed inthe second cell region, and a pad structure disposed in the pad region.The pad structure may include a plurality of stepped structures, and maybe electrically coupled to the first and second cell structures. Themethod may include forming one or more openings passing through the padstructure and exposing the circuit. The one or more openings may bedisposed between the plurality of stepped structures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D are diagrams illustrating an example structure of asemiconductor device according to an embodiment of the presentdisclosure.

FIGS. 2A and 2B are a layout diagram and a cross-sectional diagram,respectively, illustrating an example structure of a semiconductordevice according to an embodiment of the present disclosure.

FIGS. 3A to 3C are layout diagrams illustrating an example structure ofa semiconductor device according to an embodiment of the presentdisclosure.

FIGS. 4A to 8A, 4B to 8B and 9 are layout diagrams and cross-sectionaldiagrams, respectively, illustrating a method of manufacturing asemiconductor device according to an embodiment of the presentdisclosure.

FIGS. 10 and 11 are diagrams illustrating an example configuration of amemory system according to an embodiment of the present disclosure.

FIGS. 12 and 13 are diagrams illustrating an example of a computingsystem according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout.

Hereinafter, embodiments will be described in greater detail withreference to the accompanying drawings. Embodiments are described hereinwith reference to cross-sectional illustrations that are schematicillustrations of embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments should not be construed as limited to theparticular shapes of regions illustrated herein but may includedeviations in shapes that result, for example, from manufacturing. Inthe drawings, lengths and sizes of layers and regions may be exaggeratedfor clarity. Like reference numerals in the drawings denote likeelements.

Terms such as ‘first’ and ‘second’ may be used to describe variouscomponents, but they should not limit the various components. Thoseterms are only used for the purpose of differentiating a component fromother components. For example, a first component may be referred to as asecond component, and a second component may be referred to as a firstcomponent and so forth without departing from the spirit and scope ofthe present disclosure. Furthermore, ‘and/or’ may include any one of ora combination of the components mentioned.

Furthermore, a singular form may include a plural from as long as it isnot specifically mentioned in a sentence. Furthermore,“include/comprise” or “including/comprising” used in the specificationrepresents that one or more components, steps, operations, and elementsexist or are added.

Furthermore, unless defined otherwise, all the terms used in thisspecification including technical and scientific terms have the samemeanings as would be generally understood by those skilled in therelated art. The terms defined in generally used dictionaries should beconstrued as having the same meanings as would be construed in thecontext of the related art, and unless clearly defined otherwise in thisspecification, should not be construed as having idealistic or overlyformal meanings.

It is also noted that in this specification, “connected/coupled” refersto one component not only directly coupling another component but alsoindirectly coupling another component through an intermediate component.On the other hand, “directly connected/directly coupled” refers to onecomponent directly coupling another component without an intermediatecomponent.

Hereinafter, various exemplary embodiments will be described in detailwith reference to the accompanying drawings. In the drawings,thicknesses and lengths of components may be exaggerated for convenienceof illustration. In the following description, a detailed explanation ofrelated functions and constitutions may be omitted for simplicity andconciseness. Like reference numerals refer to like elements throughoutthe specification and drawings.

FIGS. 1A to 1D are diagrams illustrating an example structure of asemiconductor device according to an embodiment of the presentdisclosure. FIGS. 1A and 1B are layout diagrams, FIG. 1C is across-sectional view taken along line A-A′ of FIG. 1B, and FIG. 1D is across-sectional view taken along line B-B′ of FIG. 1B.

Referring to FIGS. 1A and 1B, a semiconductor device according to anembodiment may include a substrate, cell structures CS1 and CS2, a padstructure PS, and a circuit. The substrate may include cell regions CR1and CR2 and a pad region PR. For example, the cell regions CR1 and CR2may include first and second cell regions CR1 and CR2, and the padregion PR may be located between the first cell region CR1 and thesecond cell region CR2. Therefore, where the cell structures CS1 and CS2include first and second cell structures CS1 and CS2, the first cellstructure CS1, the pad structure PS and the second cell structure CS2may be successively arranged in a first direction I-I′. In addition, thesemiconductor device may perform an erase operation on a memory blockbasis. Each of memory blocks MB may include the first cell region CR1,the second cell region CR2, and the pad region PR located between thefirst cell region CR1 and the second cell region CR2. The first cellstructure CR1 and the second cell region CR2 may share the pad structurePS.

The first and second cell structures CS1 and CS2 may be located in thefirst and second cell regions CR1 and CR2 of the substrate,respectively. The cell structures CS1 and CS2 may include conductivelayers and insulating layers, which are alternately stacked on top ofeach other. To put it another way, each cell structure CS1 and CS2 mayhave a stacked series of conductive layers interleaved with insulatinglayers. In addition, the cell structures CS1 and CS2 may include channellayers CH passing the conductive layers and insulating layers. One ormore lowermost conductive layers may be used as source select lines. Oneor more uppermost conductive layers may be used as drain select lines.The other conductive layers may be used as word lines. Here, one or moresource select transistors, a plurality of memory cells and one or moredrain select transistors that are coupled in series to each other mayform a single memory string. The memory string may be disposed in avertical direction.

The first cell structure CS1 may include one or more first source selectlines, a plurality of first word lines and one or more first drainselect lines. For example, the plurality of first word lines stacked ontop of each other may be disposed on the one or more first source selectlines, and the one or more first drain select lines may be disposed onthe uppermost first word line. The second cell structure CS2 may includeone or more second source select lines, a plurality of second word linesand one or more second drain select lines that are successively stackedon top of one another. For example, the plurality of second word linesstacked on top of each other may be disposed on the one or more secondsource select lines, and the one or more second drain select lines maybe disposed on the uppermost second word line. Furthermore, the firstcell structure CS1 may include first vertical memory strings, and thesecond cell structure CS2 may include second vertical memory strings.

The pad structure PS may be located in the pad region PR of thesubstrate. For example, the pad structure PS may be located between thefirst cell structure CS1 and the second cell structure CS2. The padstructure PS may be in direct contact with the first and second cellstructures CS1 and CS2, and may be electrically coupled to the first andsecond cell structures CS1 and CS2. In addition, the circuit may belocated under the pad structure PS, and at least a portion of thecircuit may be exposed through at least one opening OP passing throughthe pad structure PS. The opening OP may be filled with an insulatingpattern IP. Furthermore, a plurality of openings OP may be arranged in arow along a center line CL, which extends in the first direction I-I′ ona central portion of the pad region PR. The openings OP may be locatedin the central portion of the pad region PR, and the number of openingsOP and the shapes thereof may be modified in various ways.

The pad structure PS may include conductive layers and insulating layerswhich are alternately stacked on top of each other. For example, the padstructure PS may include a stacked series of conductive layersinterleaved with insulating layers. Among the conductive layers of thepad structure PS and the conductive layers of the first and second cellstructures CS1 and CS2, conductive layers that are disposed on the samelevel may be electrically coupled to each other. In addition, the padstructure PS is partially patterned to have stepped structures havingvarious heights. In this way, pads P1 to P4 through which biases areindividually applied to the corresponding stacked conductive layers maybe formed. In addition, the conductive layers of the pad structure PSthat are not patterned may function as conductive lines (e.g.,interconnects) for electrically coupling the pads P1 to P4 to theconductive layers of the cell structures CS1 and CS2.

The pad structure PS may include first stepped structures S1 and secondstepped structures S2. In an embodiment, the first and second steppedstructures S1 and S2 may be disposed between every adjacent openings OP.The first and second stepped structures S1 and S2 may be arranged alongthe center line CL. For example, the first stepped structures S1 may bedisposed at one side of the center line CL, and the second steppedstructures S2 may be disposed at the other side of the center line CL.In an embodiment, the first stepped structures S1 and the second steppedstructures S2 may be symmetrical about the center line CL.

The first stepped structures S1 are arranged in the first direction I-I,and adjacent first stepped structures S1 may be insulated from eachother by the corresponding openings OP. The second stepped structures S2are arranged in the first direction I-I, and adjacent second steppedstructures S2 may also be insulated from each other by the correspondingopenings OP. Furthermore, adjacent first and second stepped structuresS1 and S2 that are arranged symmetrical about the center line CL may beinsulated from each other by a third slit SL3A.

The pad structure PS may include a first line structure LS1 and a secondline structure LS2. The first line structure LS1 may electrically couplethe first pads P1 to the first and second cell structures CS1 and CS2.The second line structure LS2 may electrically couple the second pads P2to the first and second cell structures CS1 and CS2. The first linestructure LS1 may be disposed between the center line CL and a secondslit SL2A. The second line structure LS2 may be disposed between thecenter line CL and a second slit SL2B. In this case, the first linestructure LS1, the first stepped structure S1, the second steppedstructure S2 and the second line structure LS2 may be successivelyarranged in the second direction II-II′. In addition, the first linestructure LS1, the openings OP and the second line structure LS2 may besuccessively arranged in the second direction II-II′.

The first line structure LS1 includes first lines L1 which are stackedon top of one another. Each of the first lines L1 electrically couplesthe first pads P1 to the first cell structure CS1 or the second cellstructure CS2. Each of the first lines L1 may electrically couple thefirst pads P1 to the first and second cell structures CS1 and CS2. Thefirst line structure LS1 has a height equal to or greater than that ofthe first stepped structure S1. The second line structure LS2 includessecond lines L2 which are stacked on top of one another. Each of thesecond lines L2 electrically couples the second pads P2 to the firstcell structure CS1 or the second cell structure CS2. Each of the secondlines L2 may electrically couple the second pads P2 to the first andsecond cell structures CS1 and CS2. The second line structure LS2 has aheight equal to or greater than that of the second stepped structure S2.The first line structure LS1 may include a first dummy stepped structureDS1 which is disposed over the stacked first lines L1. The second linestructure LS2 may include a second dummy stepped structure DS2 which isdisposed over the stacked second lines L2.

The pad structure PS may include a third stepped structure S3, which isin contact with the first cell structure CS1, and a fourth steppedstructure S4, which is in contact with the second cell structure CS2.The third stepped structure S3 is disposed between the first cellstructure CS1 and the corresponding opening OP, and includes the thirdpads P3 which are stacked on top of one another. The fourth steppedstructure S4 is disposed between the second cell structure CS2 and thecorresponding opening OP, and includes the fourth pads P4, which arestacked on top of one another. The third pads P3 may be electricallycoupled to the first cell structure CS1. For example, the third pads P3may be in direct contact with the first cell structure CS1. The fourthpads P4 may be electrically coupled to the second cell structure CS2.For example, the fourth pads P4 may be in direct contact with the secondcell structure CS2.

The semiconductor device may include first to fifth slits SL1 to SL5which pass through the first cell structure CS1, the pad structure PS orthe second cell structure CS2 in a stacking direction (e.g., a directionin which layers included in each of the first cell structure CS1, thepad structure PS, and the second cell structure CS2 are stacked). Thefirst to fifth slits SL1 to SL5 may be filled with first to fifth slitinsulating layers, respectively. Each of the first to fifth slits SL1 toSL5 may have a depth to completely pass through a corresponding stackstructure. Alternatively, each of the first to fifth slits SL1 to SL5may have a depth that partially penetrates the corresponding stackstructure.

The first slits SL1 may separate drain select lines of adjacent channellayers CH from each other, and may be disposed in the memory block MB.Each of the first slits SL1 may pass through the second cell structureCS2 in the stacking direction, and may have a depth to pass through thesecond drain select line. The first slit SL1 may extend in the firstdirection I-I′ to pass through the fourth stepped structure S4. Thefirst slit SL1 may insulate fourth pads P4 coupled to the second drainselect line, from each other. Also, the first slit SL1 may be disposedto pass through the first cell structure CS1 and the third steppedstructure S3.

The second slits SL2A and SL2B may electrically separate adjacent memoryblocks MB, and may be disposed on boundaries between the adjacent memoryblocks MB. Each of the second slits SL2A and SL2B may have a depth tocompletely pass through the first and second cell structures CS1 and CS2and the pad structure PS in the stacking direction.

The third slits SL3A and SL3B are disposed in the memory block MB, andeach have a line shape extending in the first direction I-I′. Each ofthe third slits SL3A and SL3B may have a depth to completely passthrough the first and second cell structures CS1 and CS2 in the stackingdirection. The third slit SL3A may extend to the pad region PR andoverlap with the center line CL. The third slit SL3A may traverse theplurality of openings OP, and may be interposed between adjacent firstand second stepped structure S1 and S2. Therefore, the adjacent firstand second stepped structure S1 and S2 may be insulated from each otherby the third slit SL3A. The third slits SL3B may be disposed between thecenter line CL and the second slits SL2A and SL2B, and each may have adepth to pass through the first cell structure CS2 and the third steppedstructure S3 or the second cell structure CS2 and the fourth steppedstructure S4.

The fourth and fifth slits SL4 and SL5 insulate conductive linesdisposed at the same level from each other. The fourth and fifth slitsSL4 and SL5 may be disposed in the pad structure PS. The fourth slitsSL4 may extend in the first direction I-I′, and may be coupled to thethird slits SL3B. The fifth slits SL5 may extend in the second directionII-II′, and may traverse the corresponding openings OP. The fifth slitsSL5 may be coupled to the fourth slits SL4. Accordingly, the fourth andfifth slits SL4 and SL5 may be coupled to each other in a C shape.

Each of the fourth slits SL4 may have a depth to pass through only thelines that are coupled to the source select lines. Each of the fifthslits SL5 may have a depth to completely pass through the pad structurePS. The lines coupled to the source select lines are patterned by thesecond slits SL2A and SL2B, the third slit SL3A, the fourth slit SL4 andthe fifth slits SL5. The lines that coupled to the word lines arepatterned by the second slits SL2A and SL2B, the third slit SL3A and thefifth slits SL5. As such, the source select lines and the word lines maybe patterned in different shapes by adjusting the depths of the fourthslits SL4.

Referring to FIGS. 1C and 1D, the pad structure PS may be disposed inthe pad region PR of the substrate 20, and a circuit 21 may be disposedunder the pad structure PS. The circuit 21 may include a variety ofcomponents, such as a transistor, a capacitor, and a resistor. In anembodiment, the circuit 21 may be an X-decoder X-DEC. The pad structurePS may include stacked layers 1 to 16, and each of the layers 1 to 16may include a first layer A and a second layer B. For example, the firstlayer A may be a conductive layer, and the second layer B may be aninsulating layer. Alternatively, the first layer A may be an insulatinglayer, and the second layer B may be a conductive layer.

Each of the first stepped structures S11 to S13 includes first pads P11to P13. The first pads P11 to P13 are electrically coupled to the firstlines L11 to L13, respectively. The first lines L11 to L13 electricallycouple the first pads P11 to P13 to the first source select lines of thefirst vertical memory strings and/or the second source select lines ofthe second vertical memory strings.

Each of the first stepped structures S14 includes first pads P14. Thefirst pads P14 are electrically coupled to the first lines L14,respectively. The first lines L14 electrically couple the first pads P14to the first word lines of the first vertical memory strings and thesecond word lines of the second vertical memory strings.

The first stepped structures S11 to S14 and the second steppedstructures S21 to S24 may be arranged symmetrically about the centerline CL. The first lines L11 to L14 and the second lines L21 to L24 maybe arranged symmetrically about the center line CL.

The third stepped structure S3 may include the third pads P3electrically coupled to the first drain select lines of the firstvertical memory strings. The fourth stepped structure S4 may include thefourth pads P4 electrically coupled to the second drain select lines ofthe second vertical memory strings. For reference, the third pad P3 ofthe thirteenth layer 13 may be electrically coupled to the first wordline of the first vertical memory string, and the fourth pad P4 of thethirteenth layer 13 may be electrically coupled to the second word lineof the second vertical memory string.

Here, the first cell structure CS1 and the second cell structure CS2 aredisposed on opposite sides of the pad structure PS. The first cellstructure CS1 and the second cell structure CS2 may share the padstructure PS. Therefore, compared to the case where a circuit isdisposed on only one side of the cell region, the distance between thecircuit 21 and the cell structures CS1 and CS2 may be reduced by half,and thus the RC delay may be reduced. Therefore, a program speed of thesemiconductor device may be increased.

Furthermore, the circuit 21 and the plurality of openings OP may bedisposed in the central portion of the pad region PR, and the pads aredistributed in spaces between the plurality of openings OP. Thus, thepad area PR requires a smaller area. In addition, because the pads areformed by partially patterning the pad structure and non-patternedregions are used as conductive lines (e.g., interconnects), themanufacturing process can be simplified.

FIGS. 2A and 2B are diagrams illustrating an example structure of asemiconductor device according to an embodiment of the presentdisclosure. FIG. 2A is a layout view of an interconnection structure,and FIG. 2B is a cross-sectional view of a first stepped structure,taken along a line in the first direction I-I′. The same or likeelements in FIGS. 2A and 2B are labeled with the same referencecharacters as those in FIGS. 1A to 1D, and any repetitive detaileddescription will be omitted or simplified.

Referring to FIGS. 2A and 2B, a first interconnection structure C1 mayelectrically couple first pads P11 of the first stepped structure S11 tofirst pads P13 of the first stepped structure S13. Furthermore, thefirst interconnection structure C1 may couple the first pads P11 and P13to the circuit 21. For example, the first interconnection structure C1may include first contact plugs 31 coupled to the respective first padsP11, second contact plugs 32 coupled to the respective first pads P13, athird contact plug 33 disposed in the corresponding opening OP andcoupled to the circuit 21, and a conductive line 34 which electricallycouples the first to third contact plugs 31 to 33 to each other andextends in the first direction I-I′.

A second interconnection structure C2 may electrically couple first padsP12 of the first stepped structure S12 to each other, and may couple thefirst pads P12 to the circuit 21. For example, the secondinterconnection structure C2 may include first contact plugs 35 coupledto the respective first pads P12, a second contact plug 36 disposed inthe corresponding opening OP and coupled to the circuit 21, and aconductive line 37 which electrically couples the first to third contactplugs 35 to 36 to each other and extends in the first direction I-I′.

A third interconnection structure C3 may electrically couple second padsP21 of the second stepped structure S21 to second pads P23 of a secondstepped structure S23 and to the electrically-coupled first and secondpads P21 and P23 to the circuit 21. A fourth interconnection structureC4 may couple second pads P22 of the second stepped structure S22 to thecircuit.

A fifth interconnection structure C5 may electrically couple first padsP14 of the first stepped structures S14 and second pads P24 of thesecond stepped structure S24, which are adjacent to each other in thesecond direction II-II′, to each other. Among the first and second padsP14 and P24, a first pad P14 and a second pad P24 that are disposed atthe same level are electrically coupled to each other.

A sixth interconnection structure C6 may electrically couple third padsP3 of the third stepped structure S3 to fourth pads P4 of the fourthstepped structure S4. For example, the sixth interconnection structureC6 may include fourth contact plugs 38 coupled to the respective thirdpads P3, fifth contact plugs 39 coupled to the respective fourth padsP4, and a conductive line 40 which electrically couples the fourth andfifth contact plugs 38 and 39 to each other.

For reference, depending on the respective numbers of source selecttransistors, memory cells and drain select transistors included in asingle memory string, the coupling methods may be modified. In anexample, a vertical memory string illustrated in FIGS. 2A and 2Bincludes three source select transistors, ten memory cells and threedrain select transistors. Therefore, a first pad P11 of a fourth layer 4of the first stepped structure S11 may be electrically coupled to asecond pad P21 of a fourth layer 4 of the second stepped structure S21by the fifth interconnection structure C5. Furthermore, third pads P3 ofthirteenth layers 13 of the third stepped structures S3 adjacent to eachother in the second direction II-II′ may be electrically coupled to eachother by the fifth interconnection structure C5. Although FIGS. 2A and2B illustrates an example of a vertical memory string as including threesource select transistors, ten memory cells and three drain selecttransistors, it is intended to be illustrative only and the invention isnot limited thereto, and the number of stacked layers or the couplingmethods of the interconnection structures may vary.

FIGS. 3A to 3C are layout diagrams illustrating an example structure ofa semiconductor device according to an embodiment of the presentdisclosure. FIG. 3A is a layout diagram showing conductive lines andpads coupled to source select lines. FIG. 3B is a layout diagram showingconductive lines and pads coupled to word lines. FIG. 3C is a layoutdiagram showing pads coupled to drain select lines.

Referring to FIG. 3A, the first cell structure CS1 includes first sourceselect lines SSL11 to SSL14, and the second cell structure CS2 includessecond source select lines SSL21 to SSL24. First and second pads P11 toP13 and P21 to P23 of the pad structure PS are electrically coupled tothe first and second source select lines SSL11 to SSL14 and SSL21 toSSL24.

The first pads P11 are electrically coupled to a first line L11. Thefirst pads P12 are electrically coupled to a first line L12. The firstpads P13 are electrically coupled to a first line L13. The first linesL11 to L13 disposed at the same level are insulated from each other byslits SL.

The first line L11 electrically couples the first source select lineSSL12 to the first pads P11. The first line L12 is coupled in common tothe first source select line SSL11 and the second source select lineSSL21. Thus, the first line L12 electrically couples the first andsecond source select lines SSL11 and SSL21 to the first pads P12. Thefirst line L13 electrically couples the second source select line 55L22to the first pads P13.

The second pads P21 are electrically coupled to a second line L21. Thesecond pads P22 are electrically coupled to a second line L22. Thesecond pads P23 are electrically coupled to a second line L23. Thesecond lines L21 to L23 disposed at the same level are insulated fromeach other by slits SL.

The second line L21 electrically couples the first source select lineSSL13 to the second pads P21. The second line L22 is coupled in commonto the first source select line SSL14 and the second source select lineSSL24. Thus, the second line L22 electrically couples the first andsecond source select lines SSL14 and SSL24 to the second pads P22. Thesecond line L23 electrically couples the second source select line SSL23to the second pads P23.

Therefore, the first source select lines SSL11 to SSL14 included in thefirst cell structure CS1 may be individually controlled. Furthermore,the second source select lines SSL21 to SSL24 included in the secondcell structure CS2 may be individually controlled.

Referring to FIG. 3B, the first cell structure CS1 includes first wordlines WL11 to WL14, and the second cell structure CS2 includes secondword lines WL21 to WL24. The first and second pads P14 and P24 of thepad structure PS are electrically coupled to the first and second wordlines WL11 to WL14 and WL21 to WL24.

The first pads P14 are electrically coupled to first lines L14, and thesecond pads P24 are electrically coupled to second lines L24. Among thefirst lines L14 and the second lines L24, a first line L14 and a secondline L24 disposed at the same level are insulated from each other by aslit SL.

The first line L14 is coupled in common to the first word lines WL11 toWL12 and the second word lines WL21 to WL22. Thus, the first line L14electrically couples the first and second word lines WL11 to WL12 andWL21 to WL22 to the first pads P14. The second line L24 is coupled incommon to the first word lines WL13 to WL14 and the second word linesWL23 to WL24. Thus, the second line L24 electrically couples the firstand second word lines WL13 to WL14 and WL23 to WL24 to the second padsP24.

Referring to FIG. 3C, the first cell structure CS1 includes first drainselect lines DSS11 to DSL18, and the second cell structure CS2 includessecond drain select lines DSL21 to DSL28. Furthermore, third pads P31 toP38 of the pad structure PS are electrically coupled to the first drainselect lines DSL11 to DSL18, respectively. Fourth pads P41 to P48 areelectrically coupled to the second drain select lines DSL21 to DSL 28,respectively. The third pads P31 to P38 may be in direct contact withthe first drain select lines DSL11 to DSL18, respectively. The fourthpads P41 to P48 may be in direct contact with the second drain selectlines DSL21 to DSL28, respectively.

FIGS. 4A to 9 are layout diagrams and cross-sectional diagramsillustrating a method of manufacturing a semiconductor device accordingto an embodiment of the present disclosure. FIGS. 4A, 5A, 6A, 7A, 8A,and 9 are layout diagrams, and FIGS. 4B, 5B, 6B, 7B, and 8B arecross-sectional views. The same or like elements in FIGS. 4A to 9 arelabeled with the same reference characters as those in previousdrawings, and any repetitive detailed description will be omitted orsimplified.

Referring to FIGS. 4A and 4B, a circuit 61 is formed on the substrate 60including the first cell region CR1, the second cell region CR2 and thepad region PR. For example, an X-decoder is formed on the pad region PRof the substrate 60, and then an interlayer insulating layer is formed.Subsequently, stacked layers 41 to 44 are formed on the substrate 60.The stacked layers 41 to 44 are formed on the first cell region CR1, thepad region PR and the second cell region CR2 of the substrate 60 in amanner that covers the circuit 61.

Thereafter, although not illustrated, channel layers, which pass throughthe stacked layers 41 to 44 of the first and second cell regions CR1 andCR2, and data storage layers, which enclose the sidewalls of therespective channel layers, may be formed. Each of the data storagelayers may include a floating gate containing materials such as silicon,charge trap material (e.g., nitrides), phase change material, nanodots,and so forth.

Thereafter, first slits SL1 passing through the stacked layers 41 to 44are formed, and first slit insulating layers SLI1 are formed in thefirst slits SL1. The first slits SL1 may be disposed in the pad regionPR. Each first slit SL1 may have a line shape extending in the firstdirection I-I′. The first slits SL1 pass through the stacked layers 41to 44 in the stacking direction (e.g., a direction in which the layers41 to 44 are stacked). The first slits SL1 may be spaced apart from eachother. The first slits SL1 may have the same length as each other.Alternatively, the first slits SL1 may have different lengths.

For instance, in forming a stack structure in which n groups arestacked, a first group G1 is formed, and then the first slit SL1 and thefirst slit insulating layer SLI1 are formed. In this way, the firstgroup G1 may have a pattern different from that of the remaining secondto n^(th) groups. Here, n is a natural number greater than or equal tothree.

Referring to FIGS. 5A and 5B, stacked layers 45 to 56 of second ton^(th) groups are formed on the stacked layers 41 to 44 of the firstgroup G1. In this way, the stacked layers 41 to 56 may form a stackstructure ST. The stack structure ST may include first and second cellstructures, and a pad structure. The first cell structure may be aportion of the stack structure ST where the first cell region CR1 isformed. The second cell structure may be a portion of the stackstructure ST where the second cell region CR2 is formed. The padstructure may be a portion of the stack structure ST where the padregion PR is formed. That is, different portions of the single stackstructure ST may perform different functions.

Each of the layers 41 to 56 may include a first material layer C and asecond material layer D. For example, in each of the layers 41 to 56,the first material layer C may be disposed on the second material layerD. Alternatively, the second material layer D may be disposed on thefirst material layer C.

The first material layers C are provided to form word lines, selectlines, pads, etc., and the second material layers D are provided toinsulate the stacked conductive layers from each other. For example,each of the first material layers C may be formed of a sacrificial layerincluding a nitride material or the like, and each of the secondmaterial layers D may be formed of an insulating layer including anoxide material or the like. Alternatively, each of the first materiallayers C may be formed of a conductive layer including polysilicon,tungsten, etc., and each of the second material layers D may be formedof an insulating layer including an oxide material or the like. As afurther alternative, each of the first material layers C may be formedof a conductive layer including doped polysilicon or the like, and eachof the second material layers D may be formed of a sacrificial layerincluding undoped polysilicon or the like.

The stacked layers 41 to 56 may be grouped depending on the shape oflines, the positions of pads, etc. In an example illustrated in FIGS. 5Aand 5B, n is three, and thus the stacked layers 41 to 56 are groupedinto three groups, which are a first group (41 to 44; G1), a secondgroup (45 to 52; G2), and a third group (53 to 56; G3). Here, the shapeof lines in the first group G1 differs from that of the second or thirdgroup G2, G3 in that it is additionally patterned by a first slitinsulating layer SLI1. Furthermore, in the first and second groups G1and G2, the pads are disposed in the central portion of the pad regionPR, but the pads of the third group G3 are in contact with the cellstructures. The number of stacked groups and the number of stackedlayers included in each group may vary.

Subsequently, a first mask pattern 57 is formed on the stacked structureST. The first mask pattern 57 includes first openings OP1 each of whichhas a line shape extending in the second direction II-II′. Thereafter,an n^(th) group is partially patterned using the first mask pattern 57,and thus a plurality of stepped structures exposing layers of the n^(th)group in a predetermined pattern.

For example, in the case where n is three, the layer 56 of the thirdgroup G3 is etched using the first mask pattern 57 as an etch barrier,and then the first mask pattern 57 is reduced such that a first openingOP1 extends in the first direction I-I′. Thereafter, the layers 55 and56 of the third group G3 are etched using the reduced first mask pattern57 as an etch barrier. In this way, the layers 53 to 56 of the thirdgroup G3 of each stepped structure may be exposed in a predeterminedpattern by repeatedly performing an etching operation and an operationof reducing the first mask pattern 57. Thereby, the first line structureLS1, which includes the first lines L1 and the first dummy steppedstructure DS1, and the second line structure LS2, which includes thesecond lines L2 and the second dummy stepped structure DS2, may beformed. Furthermore, the third stepped structure S3 in contact with thefirst cell structure CS1 and the fourth stepped structure S4 in contactwith the second cell structure CS2 may be formed. Subsequently, thefirst mask pattern 57 is removed.

Referring to FIGS. 6A, 6B, 7A and 7B, the first to (n−1)^(th) groups ofthe stacked structure ST are partially patterned to form a plurality ofstepped structures exposing layers of the first to (n−1)^(th) groups inpredetermined patterns. For example, in the case where n is three, aplurality of stepped structures exposing layers of the first and secondgroups in predetermined patterns may be formed.

First, a second mask pattern 58 including second openings OP2 is formedon the stacked structure ST, and then the layers 50 to 53 are etchedusing the second mask pattern 58 as an etch barrier. Subsequently, thesecond mask pattern 58 is removed. Thereafter, a third mask pattern 59including third openings OP3 is formed on the stacked structure ST, andthen the layers 42 to 49 are etched using the third mask pattern 59 asan etch barrier. Thereby, a first stepped structure S1 and a secondstepped structure S2 exposing the layers 41 to 52 in predeterminedpatterns may be formed.

The second and third mask patterns 58 and 59 are formed to cover thefirst and second line structures LS1 and LS2 and the third and fourthstepped structure S3 and S4. The second and third mask patterns 58 and59 include the second and third openings OP2 and OP3, which have islandshapes and expose regions where the first and second stepped structuresS1 and S2 will be formed. Depending on the number of stacked layers, thesecond openings OP2 and the third openings OP3 may overlap, at least inpart, each other. The second openings OP2 and the third openings OP3 mayhave the same width as each other. Alternatively, the second openingsOP2 and the third openings OP3 may have different widths from eachother. Furthermore, the number of etched layers may vary.

Referring to FIGS. 8A and 8B, an interlayer insulating layer 70 isformed on the stacked structure ST, and then fourth openings OP4 areformed in a manner that passes through the interlayer insulating layer70 and the stacked structure ST. Thereafter, insulating patterns 71 areformed in the fourth openings OP4. For example, the fourth openings OP4are formed in a manner that passes through the pad region PR, that is,the pad structure of the stacked structure ST. Each of the fourthopenings OP4 has a depth to completely pass through the pad structureand expose the circuit 61.

Referring to FIG. 9, second to fifth slits SL2, SL3A, SL3B, SL4 and SL5are formed in a manner that passes through the stacked structure ST. Thesecond to fourth slits SL2, SL3A, SL3B and SL4 extend in the firstdirection I-I′, and the fifth slit SL5 extends in the second directionII-II′. Furthermore, the third slit SL3A and the fifth slit SL5intersect each other, and the third and fifth slits SL3B and SL5 and thefirst slit SL1 are coupled to each other in a C shape.

The second slits SL2 electrically separates adjacent memory blocks MBand are disposed on boundaries between the adjacent memory blocks MB.Each of the second slits SL2 has a depth to completely pass through thestacked layers 41 to 56. The fourth slits SL4 separate the drain selectlines that are disposed at the same level, from each other, and eachhave a depth to pass through the layers 54 to 56, which are provided tobe used as the drain select lines. The third slits SL3A and SL3Bseparate the source select lines that are disposed at the same levelseparate the drain select lines that are disposed at the same level andeach have a depth to completely pass through the stacked layers 41 to56. The third slit SL3A is disposed in the center of the memory blockand traverses the plurality of the fourth openings OP4. Furthermore, thefifth slit SL5 separates the source select lines that are disposed atthe same level and has a depth to completely pass through the stackedstructures 41 to 56.

In an embodiment, the source select lines that are disposed at the samelevel are separated from each other by the first, third and fifth slitsSL1, SL3A, SL3B and SL5. Furthermore, the drain select lines that aredisposed at the same level are separated from each other by the thirdand fourth slits SL3A, SL3B and SL4.

The second to fifth slits SL2, SL3A, SL3B, SL4 and SL5 may be formed atthe same time. Alternatively, two or more steps may be used to form thesecond to fifth slits SL2, SL3A, SL3B, SL4 and SL5. For example, thesecond, fourth, and fifth slits SL2, SL4, and SL5 are formed, andthereafter second, fourth, and fifth slit insulating layers are formedtherein. Subsequently, the third slits SL3A and SL3B that intersect withthe fifth slits SL5 are formed, and then third slit insulating layersare formed therein.

Furthermore, after slit insulating layers, which are provided to be usedas supports, are formed in the second, fourth and fifth slits SL2, SL4and SL5, an additional process using the third slits SL3A and SL3B maybe performed. For example, in the case where the first material layers Care sacrificial layers and the second material layers D are insulatinglayers, conductive layers may substitute for the first material layersC. In another example, in the case the first material layers C areconductive layers and the second material layers D are insulatinglayers, the first material layers C may be silicidized. In addition, inthe case the first material layers C are conductive layers and thesecond material layers D are sacrificial layers, insulating layers maysubstitute for the first material layers C.

FIG. 10 is a diagram illustrating an example configuration of a memorysystem according to an embodiment of the present disclosure.

Referring FIG. 10, the memory system 1000 according to an embodiment ofthe present invention includes a memory device 1200 and a controller1100.

The memory device 1200 is used to store data information having varioustypes of data such as text, graphics and software codes. The memorydevice 1200 may be a non-volatile memory and include the structuredescribed with reference to FIGS. 1A to 9. In addition, the memorydevice 1200 may include a first cell structure, a second cell structure,a pad structure, a circuit, and one or more openings. The pad structuremay be disposed between the first cell structure and the second cellstructure, and may be electrically coupled to the first and second cellstructures. The pad structure may have a plurality of steppedstructures. The circuit may be disposed under the pad structure. The oneor more openings may pass through the pad structures and expose thecircuit. The one or more openings may be disposed between the pluralityof stepped structures. The structure of the memory device 1200 and themanufacturing method thereof are the same as those described above;therefore detailed explanation thereof will be omitted.

The controller 1100 may be coupled to a host and the memory device 1200,and may access the memory device 1200 in response to a request from thehost. For example, the controller 1100 may control read, write, remove,and background operations of the memory device 1200.

The controller 1100 may include a random access memory (RAM) 1110, acentral processing unit (CPU) 1120, a host interface 1130, an errorcorrection code (ECC) circuit 1140, a memory interface 1150, and soforth.

The RAM 1110 may be used as a main memory of the CPU 1120, a cachememory between the memory device 1200 and the host, a buffer memorybetween the memory device 1200 and the host, or the like. For reference,the RAM 1110 may be replaced with a static random access memory (SRAM),a read only memory (ROM), or the like.

The CPU 1120 may control the overall operation of the controller 1100.For example, the CPU 1120 may operate firmware such as a flashtranslation layer (FTL) stored in the RAM 1110.

The host interface 1130 may interface with the host. For example, thecontroller 1100 may communicate with the host through at least one ofvarious interface protocols such as a universal serial bus (USB)protocol, a multimedia card (MMC) protocol, a peripheral componentinterconnection (PCI) protocol, a PCI-express (PCI-E) protocol, anadvanced technology attachment (ATA) protocol, a serial-ATA protocol, aparallel-ATA protocol, a small computer small interface (SCSI) protocol,an enhanced small disk interface (ESDI) protocol, and an integrateddrive electronics (IDE) protocol, a private protocol, and the like.

The ECC circuit 1140 may use an error correction code (ECC) to detectand correct errors included in data read from the memory device 1200.

The memory interface 1150 may interface with the memory device 1200. Forexample, the memory interface 1150 may include a NAND interface or a NORinterface. For reference, the controller 1100 may further include abuffer memory (not illustrated) that temporarily stores data. The buffermemory may be used to temporarily store data to be transferred from thehost interface 1130 to an external device or data to be transferred fromthe memory interface 1150 to the memory device 1200. The controller 1100may further include a ROM for storing code data that is used tointerface with the host.

Since the memory system 1000 according to an embodiment includes thememory device 1200 having improved integration density andcharacteristics, the memory system 1000 may be miniaturized while havinggood characteristics.

FIG. 11 is a diagram illustrating an example configuration of a memorysystem according to an embodiment of the present disclosure. Here, anyrepetitive detailed description will be omitted or simplified.

Referring to FIG. 11, the memory system 1000′ according to an embodimentmay include a memory device 1200′ and a controller 1100. The controller1100 may include a RAM 1110, a CPU 120, a host interface 1130, an ECCcircuit 1140, a memory interface 1150, and so forth.

The memory device 1200′ may be a non-volatile memory device, and mayinclude the memory strings described above with reference to FIGS. 1A to9. In addition, the memory device 1200 may include a first cellstructure, a second cell structure, a pad structure, a circuit, and oneor more openings. The pad structure may be disposed between the firstcell structure and the second cell structure, and may be electricallycoupled to the first and second cell structures. The pad structure mayhave a plurality of stepped structures. The circuit may be disposedunder the pad structure. The one or more openings may pass through thepad structures and expose the circuit. The one or more openings may bedisposed between the plurality of stepped structures. The structure ofthe memory device 1200′ and the manufacturing method thereof are thesame as those described above; therefore detailed explanation thereofwill be omitted.

Furthermore, the memory device 1200′ may be a multi-chip packageincluding a plurality of memory chips. The plurality of memory chips aredivided into a plurality of groups. The plurality of groups maycommunicate with the controller 1100 through first to k^(th) channelsCH1 to CHk. The memory chips of each group may be suitable forcommunicating with the controller 1100 through a common channel. Thememory system 1000′ may be modified such that each single memory chip isconnected to a corresponding single channel.

As described above, according to an embodiment, since the memory system1000′ includes the memory device 1200′ having improved integrationdensity and characteristics, the memory system 1000′ may be miniaturizedwhile having good characteristics. The memory device 1200′ may befabricated in a form a multi-chip package to improve the data storagecapacity of the memory system 1000′ and to enhance the driving speedthereof.

FIG. 12 is a diagram illustrating an example configuration of acomputing system according to an embodiment of the present disclosure.Here, any repetitive detailed description will be omitted or simplified.

Referring to 12, the computing system 2000 according to an embodiment ofthe present disclosure may include a memory device 2100, a CPU 2200, aRAM 2300, a user interface 2400, a power supply 2500, a system bus 2600,and so forth.

The memory device 2100 may store data provided via the user interface2400, data processed by the CPU 2200, etc. The memory device 2100 may beelectrically coupled to the CPU 2200, the RAM 2300, the user interface2400, the power supply 2500, etc. by the system bus 2600. For example,the memory device 2100 may be coupled to the system bus 2600 via acontroller (not illustrated). Alternatively, the memory device 2100 maybe directly connected to the system bus 2600. In the case where thememory device 2100 is directly connected to the system bus 2600, thefunction of the controller may be performed by the CPU 2200, the RAM2300, etc.

The memory device 2100 may be a non-volatile memory and include thememory strings described above with reference to FIGS. 1A to 9. Inaddition, the memory device 2100 may include a first cell structure; asecond cell structure; a pad structure, a circuit, and one or moreopenings. The pad structure may be disposed between the first cellstructure and the second cell structure, and may be electrically coupledto the first and second cell structures. The pad structure may have aplurality of stepped structures. The circuit may be disposed under thepad structure. The one or more openings may pass through the padstructures and expose the circuit. The one or more openings may bedisposed between the plurality of stepped structures. The structure ofthe memory device 2100 and the manufacturing method thereof are the sameas those described above; therefore detailed explanation thereof will beomitted.

In addition, as described above with reference to FIG. 11, the memorydevice 2100 may be a multi-chip package configured with a plurality ofmemory chips.

The computing system 2000 having the above-mentioned configuration maybe provided as one of various elements of an electronic device such as acomputer, a ultra mobile PC (UMPC), a workstation, a net-book, apersonal digital assistants (PDA), a portable computer, a web tablet, awireless phone, a mobile phone, a smart phone, an e-book, a portablemultimedia player (PMP), a game console, a navigation device, a blackbox, a digital camera, a 3-dimensional television, a digital audiorecorder, a digital audio player, a digital picture recorder, a digitalpicture player, a digital video recorder, a digital video player, adevice capable of transmitting/receiving information in an wirelessenvironment, one of various devices for forming a home network, one ofvarious electronic devices for forming a computer network, one ofvarious electronic devices for forming a telematics network, an RFIDdevice, or the like.

As described above, since the computing system 2000 according to anembodiment includes the memory device 2100 having improved integrationdensity and characteristics, the computing system 2000 may beminiaturized while having good characteristics.

FIG. 13 is a diagram illustrating a computing system according to anembodiment of the present disclosure.

Referring to FIG. 13, the computing system 3000 according to anembodiment of the present disclosure may include a software layercontaining an operating system 3200, an application 3100, a file system3300, a translation layer 3400, and so forth. The computing system 300may include a hardware layer such as a memory device 3500.

The operating system 3200 may manage software resources and hardwareresources, etc. of the computing system 3000 and control programexecution of a CPU. The application 3100 may include various applicationprograms executed by the computing system 3000, and may be a utilityexecuted by the operating system 3200.

The file system 3300 may refer to a logical structure that is providedto control data, files, etc. in the computing system 3000. The filesystem 3300 may organize files or data to be stored in the memory device3500 or the like according to a given rule. The file system 3300 may bedetermined depending on the operating system 3200 used in the computingsystem 3000. For example, if the operating system 3200 is Microsoft'sWindows-based system, the file system 3300 may be a file allocationtable (FAT), an NT file system (NTFS), or the like. If the operatingsystem 3200 is a Unix/Linux-based system, the file system 3300 may be anextended file system (EXT), a Unix file system (UFS), a journaling filesystem (JFS), or the like.

Although the operating system 3200, the application 3100 and the filesystem 3300 are expressed as separate blocks in the drawing, theapplication 3100 and the file system 3300 may be included in theoperating system 3200.

The translation layer 3400 may translate an address into a suitable formfor the memory device 3500 in response to a request from the file system3300. For example, the translation layer 3400 may translate a logicaladdress produced by the file system 3300 into a physical address of thememory device 3500. Mapping information of the logical address andphysical address may be stored in an address translation table. Forexample, the translation layer 3400 may be a flash translation layer(FTL), a universal flash storage link layer (ULL), or the like.

The memory device 3500 may be a non-volatile memory. The memory device3500 may include the memory strings described above with reference toFIGS. 1A to 9. In addition, the memory device 3500 may include a firstcell structure, a second cell structure, a pad structure, a circuit, andone or more openings. The pad structure may be disposed between thefirst cell structure and the second cell structure, and may beelectrically coupled to the first and second cell structures. The padstructure may have a plurality of stepped structures. The circuit may bedisposed under the pad structure. The one or more openings may passthrough the pad structures and expose the circuit. The one or moreopenings may be disposed between the plurality of stepped structures.The structure of the memory device 3500 and the manufacturing methodthereof are the same as those described above; therefore detailedexplanation thereof will be omitted.

The computing system 300 having the above-mentioned configuration may bedivided into an operating system layer which is operated in an upperlevel region and a controller layer which is operated in a lower levelregion. The application 3100, the operating system 3200, and the filesystem 3300 may be included in the operating system layer and driven byan operating memory of the computing system 3000. The translation layer3400 may be included in the operating system layer or the controllerlayer.

As described above, since the computing system 3000 according to theembodiment includes the memory device 3500 having improved integrationdensity and characteristics, the computing system 3000 may beminiaturized while having good characteristics.

In accordance with embodiments, the program speed may be improved byreducing the distance between a circuit and a cell structure. Inaddition, the integration density may be improved by reducing the areaof a pad region, and the manufacturing process may be simplified.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A semiconductor device comprising: a circuit; apad structure disposed over the circuit, the pad structure comprising afirst stepped structure including first pads stacked on top of oneanother, a second stepped structure including second pads stacked on topof one another, and a third stepped structure including third padsstacked on top of one another; a first opening disposed between thefirst stepped structure and the second stepped structure and passingthrough the pad structure and expose the circuit; a second openingdisposed between the second stepped structure and the third steppedstructure and passing through the pad structure and expose the circuit;a first interconnection structure electrically coupling the first padsand the third pads to each other and coupling the first and third padsto the circuit through the first opening or the second opening; and asecond interconnection structure electrically coupling the second padsto each other and coupling the second pads to the circuit through thefirst opening or the second opening.
 2. The semiconductor device ofclaim 1, wherein the first stepped structure and the second steppedstructure are symmetrical about the first opening, and each of the firstand second stepped structure has a stepped shape in which a height of aportion of the stepped structure is increased as the portion of thestepped structure gets closer to the first opening.
 3. The semiconductordevice of claim 1, wherein the second stepped structure and the thirdstepped structure are symmetrical about the second opening, and each ofthe second and third stepped structures has a stepped shape in which aheight of a portion of the stepped structure is decreased as the portionof the stepped structure gets closer to the second opening.
 4. Thesemiconductor device of claim 1, wherein the pad structure comprises: afirst line structure including first lines stacked on top of oneanother, the first lines being electrically coupled to the respectivefirst pads; a second line structure including second lines stacked ontop of one another, the second lines being electrically coupled to therespective second pads; and a third line structure including third linesstacked on top of one another, the third lines being electricallycoupled to the respective third pads, and wherein, among the first tothird lines, first to third lines that are disposed at the same levelare insulated from each other.
 5. The semiconductor device of claim 4,further comprising: a first cell structure including first source selectlines stacked on top of one another and second source select linesstacked on top of one another, and being formed such that, among thefirst and second source select lines, a first source select line and asecond source select line that are disposed at the same level areinsulated from each other; and a second cell structure including thirdsource select lines stacked on top of one another and fourth sourceselect lines stacked on top of one another, and being formed such that,among the third and fourth source select lines, a third source selectline and a fourth source select line that are disposed at the same levelare insulated from each other, wherein the first lines are electricallycoupled to the respective second source select lines, each of the secondlines is coupled in common, among the first and third source selectlines, to a first source select line and a third source select line thatare disposed at the same level, and the third lines are electricallycoupled to the respective fourth source select lines.
 6. A semiconductordevice comprising: a first cell structure; a second cell structure; apad structure disposed between the first cell structure and the secondcell structure and electrically coupled to the first and second cellstructures, the pad structure having a plurality of stepped structures;a circuit disposed under the pad structure; and one or more openingspassing through the pad structure and exposing the circuit, the one ormore openings being disposed between the plurality of steppedstructures.
 7. The semiconductor device of claim 6, wherein theplurality of stepped structures comprise: a first stepped structurecomprising first pads stacked on top of one another, the first padsbeing electrically coupled to the first cell structure; a second steppedstructure comprising second pads stacked on top of one another, thesecond pads being electrically coupled to the first and second cellstructures; and a third stepped structure comprising third pads stackedon top of one another, the third pads being electrically coupled to thesecond cell structure.
 8. The semiconductor device of claim 7, whereinthe openings comprise: a first opening disposed between the firststepped structure and the second stepped structure and formed toinsulate the first pads and the second pads from each other; and asecond opening disposed between the second stepped structure and thethird stepped structure and formed to insulate the second pads and thethird pads from each other.
 9. The semiconductor device of claim 7,further comprising: a first interconnection structure electricallycoupling the first pads and the third pads to each other and couplingthe first and third pads to the circuit through the openings; and asecond interconnection structure electrically coupling the second padsto each other and coupling the second pads to the circuit through theopenings.
 10. The semiconductor device of claim 7, wherein the padstructure comprises: a first line structure comprising first linesstacked on top of one another, the first lines being electricallycoupled to the respective first pads; a second line structure comprisingsecond lines stacked on top of one another, the second lines beingelectrically coupled to the respective second pads; and a third linestructure comprising third lines stacked on top of one another, thethird lines being electrically coupled to the respective third pads, andwherein, among the first to third lines, first to third lines that aredisposed at the same level are insulated from each other.
 11. Thesemiconductor device of claim 10, wherein: the first cell structureincludes first source select lines stacked on top of one another andsecond source select lines stacked on top of one another, and among thefirst and second source select lines, a first source select line and asecond source select line that are disposed at the same level areinsulated from each other; and the second cell structure includes thirdsource select lines stacked on top of one another and fourth sourceselect lines stacked on top of one another, and among the third andfourth source select lines, a third source select line and a fourthsource select line that are disposed at the same level are insulatedfrom each other.
 12. The semiconductor device of claim 11, wherein: thefirst lines are electrically coupled to the respective first sourceselect lines; each of the second lines is coupled in common, among thesecond and third source select lines, to a second source select line anda third source select line that are disposed at the same level; and thethird lines are electrically coupled to the respective fourth sourceselect lines.
 13. The semiconductor device of claim 7, furthercomprising: a slit insulating layer extending in one direction totraverse the openings and passing through the pad structure in astacking direction; a fourth stepped structure facing the first steppedstructure such that the slit insulating layer is disposed between thefirst and fourth stepped structures, the fourth stepped structurecomprising fourth pads stacked on top of one another, the fourth padsbeing electrically coupled to the first cell structure; a fifth steppedstructure facing the second stepped structure such that the slitinsulating layer is disposed between the second and fifth steppedstructures, the fifth stepped structure comprising fifth pads stacked ontop of one another, the fifth pads being electrically coupled to thefirst and second cell structures; and a sixth stepped structure facingthe third stepped structure such that the slit insulating layer isdisposed between the third and sixth stepped structures, the sixthstepped structure comprising sixth pads stacked on top of one another,the sixth pads being electrically coupled to the second cell structure.14. The semiconductor device of claim 13, wherein the openings comprise:a first opening disposed between the first and fourth stepped structuresand the second and fifth stepped structures and formed to insulate thefirst and fourth pads from the second and fifth pads; and a secondopening disposed between the second and fifth stepped structures and thethird and sixth stepped structures and formed to insulate the second andfifth pads from the third and sixth pads.
 15. The semiconductor deviceof claim 13, further comprising: a first interconnection structureelectrically coupling the first pads and the third pads to each otherand coupling the first and third pads to the circuit through theopenings; a second interconnection structure electrically coupling thesecond pads with each other and coupling the second pads to the circuitthrough the openings; a third interconnection structure configured toelectrically coupling the fourth pads and the sixth pads to each otherand coupling the fourth and sixth pads to the circuit through theopenings; and a fourth interconnection structure configured toelectrically coupling the fifth pads to each other and coupling thefifth pads to the circuit through the openings.
 16. The semiconductordevice of claim 13, wherein the pad structure comprises: a first linestructure comprising first lines stacked on top of one another, thefirst lines being electrically coupled to the respective first pads; asecond line structure comprising second lines stacked on top of oneanother, the second lines being electrically coupled to the respectivesecond pads; a third line structure comprising third lines stacked ontop of one another, the third lines being electrically coupled to therespective third pads; a fourth line structure comprising fourth linesstacked on top of one another, the fourth lines being electricallycoupled to the respective fourth pads; a fifth line structure comprisingfifth lines stacked on top of one another, the fifth lines beingelectrically coupled to the respective fifth pads; and a sixth linestructure comprising sixth lines stacked on top of one another, thesixth lines being electrically coupled to the respective sixth pads,wherein, among the first to sixth lines, first to sixth lines that aredisposed at the same level are insulated from each other.
 17. Thesemiconductor device of claim 16, wherein: the first cell structurecomprises first to fourth source select lines insulated from each other,and the second cell structure comprises fifth to eighth source selectlines insulated from each other; the first lines are electricallycoupled to the respective second source select lines; each of the secondlines is coupled in common, among the first and fifth source selectlines, to a first source select line and a fifth source select line thatare disposed at the same level; the third lines are electrically coupledto the respective sixth source select lines; the fourth lines areelectrically coupled to the respective third source select lines; eachof the fifth lines is coupled in common, among the fourth and eighthsource select lines, to a fourth source select line and an eighth sourceselect line that are disposed at the same level; and the sixth lines areelectrically coupled to the respective seventh source select lines. 18.The semiconductor device of claim 7, wherein the first stepped structureand the second stepped structure are symmetrical, and the second steppedstructure and the third stepped structure are symmetrical.